/**
 Copyright (c) 2007, Alek Dembowski

 All rights reserved.

 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 * The names of its contributors may not be used to endorse or promote products derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

package com.darkpegasus.trillian.parser;

import com.darkpegasus.trillian.exception.ConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Date;

/**
 * @author Alek
 */
public class LogEntry {
    private static DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    public static final String enc = "UTF-8";

    static public LogEntry buildEntry(String messageXml) throws ParserConfigurationException, SAXException {
        Element element = null;

        DocumentBuilder builder = docFactory.newDocumentBuilder();
        try {
            ByteArrayInputStream inputStream = new ByteArrayInputStream(messageXml.getBytes(enc));
            Document document = builder.parse(inputStream);
            element = document.getDocumentElement();
        } catch (IOException e) {
            // Catch and just print... this should never happen since
            // it's just a ByteArrayInputStream from a String
            e.printStackTrace();
        }

        return new LogEntry(element);
    }

    private Element element;

    private LogEntry(Element element) {
        this.element = element;
    }

    public String getType() {
        return element.getTagName();
    }

    public String getTextField(String messageField) {
        return decodeText(element.getAttribute(messageField));
    }

    public Date getTimestampField(String messageField){
        return parseTimestamp(element.getAttribute(messageField));
    }

    /**
     * Trillian timestamps are # of seconds since 1970. Date constructor expects # millis since 1970
     * @param timestamp
     * @return Appropriate Date
     */
    static Date parseTimestamp(String timestamp){
        long timestampValue = Integer.parseInt(timestamp) * 1000L;

        return new Date(timestampValue);
    }

    static String decodeText(String encodedText) {
        if(encodedText == null){
            return null;
        }

        try {
            return URLDecoder.decode(encodedText, enc);
        } catch (UnsupportedEncodingException e) {
            // Should never get here... from the docs enc should always be recorded
            throw new ConfigurationException("Encoding " + enc + " doesn't seem to be supported on this system. ", e);
        }
    }
}
